Most of the dozens of lawmakers who spoke in the three-hour debate did not agree that Trump should be excluded. They instead argued that he should be allowed to visit Britain so that his ideas could be thrashed out openly and shot down.

Under fire ... British MPs have used some colourful language to describe Donald Trump. Picture: AFP/Nicholas KammSource:AFP

Under British law, any petition supported by 100,000 people — who must provide and confirm an email address — is considered for parliamentary debate.

The debate in a small parliamentary committee room was purely symbolic — Britain’s government has already said it will not ban Trump and lawmakers did not even vote on the issue.

But it did at least yield up some colourful language.

“Donald Trump is a fool. He’s free to be a fool. He’s not free to be a dangerous fool on our shores,” argued Jack Dromey, a senior MP in the main opposition Labour Party, who wants him banned.

Debate ... British Conservative Party politician Victoria Atkins speaks during a debate among members of parliament gathered to discuss whether to ban US presidential hopeful Donald Trump. Picture: AFP/PRUSource:AFP

Gavin Newlands of the Scottish National Party called Trump an “idiot” whose popularity shows “how far the country of Lincoln and Roosevelt has fallen”.

Alex Chalk of the governing Conservative Party argued that Trump’s behaviour was “buffoonery” which should be met with “the classic British response of ridicule”.

Meanwhile, another Conservative, Victoria Atkins, resorted to British slang to refer to him as “bonkers” and a “wazzock” (a stupid person).

Labour Party legislator Paul Flynn cautioned it would be wrong to give Trump a “halo of victimhood” by banning him from the UK.

Flynn said Trump’s remarks had caused “a great deal of upset,” but “I think we might already be in error in giving him far too much attention.”

UK debate ... More than 575,000 people have signed an online petition calling for Trump to be blocked for “hate speech” after he called for a temporary ban on Muslims entering the US. Picture: Supplied.Source:AFP

Some MPs condemned the fact that it was being held at all. Conservative Edward Leigh argued that giving the property baron publicity “would only play into Mr Trump’s hands”.

Another Conservative, Adam Holloway, added: “I feel we should almost apologise to the people of the United States — it’s for them to decide on Mr Trump’s views, not us.”

Trump has warned he would end all current and future investments in the UK if banned from entering the country.

“Westminster would create a dangerous precedent and send a terrible message to the world that the United Kingdom opposes free speech and has no interest in attracting inward investment,” his Trump Organization said in statement.

Trump is leading the polls for the Republican nomination for the White House ahead of the US Presidential election in November.

He sparked fierce controversy last month when he called for a “complete shutdown of Muslims entering the United States until our country’s representatives can figure out what the hell is going on”.

That call came in the wake of an attack in California by a radicalised Muslim couple that left 14 people dead.

Trump also labelled Mexican immigrants rapists and drug dealers.

Trump owns a Scottish golf course, and his mother was born in Scotland.